Alkyd resins from dicyclopentadiene dicarboxylic acids and polyhydric alcohols



United States Patent .A-LKYD :RESINS :FROM DICYCLOPENTADIENE .DI- ggfiggiYLIC ACIDS POLYHYDRIC AL- Chariles A. Cohen, Roselle Park, NJ., and Louis A. .Mrkeska, Dunedin, F-la., assignors -t0 'Esso Research and Engineering Company, a corporation'of Delaware N0 Drawing. Application August '23,, 1955 Serial No. "530,198

12 Claims. (Cl. 260-22) This invention relates to the production of polycyclic -dibasic acids and of improved surface coating compositions made from the same. This application is a cont1nuat1on-m-part of copending applications, Serial No.

268,122, filed January 24, 1952 now Patent No. 2,716,-

mar'ily from cyclopentadiene, alkyl-isubstituted cyclopentadienes, hydrogenated derivatives of cyclopentadiene and mixtures thereof.

'In a preferred aspect, this invention is concerned with the production of new and useful oil-modified and/or fatty acid modified alkyd resins derived from dicyclo- .pentadiene dicarboxylic' acid compounds such as dicyclopentadiene dicarboxylic acid, alkyl dicyclopentadiene dicarboxylic acids such as methyl and dimethyl dicyclopentadiene dicarboxylic acids, dicarboxylic acids derived from mixtures of 'cycl'opentadiene and methyl and dimethyl dicyclopentadiene, and/or hydrogenated derivatives of the above dicarboxylic acids per se or in admixture. The above 'dicarboxylic acids comprise the subject matter of the above-identified patent applications and are 'coreacted in an amount of 100 to 150 parts by weight with to 6'0 partsby weight of a p'oly'functional alcohol preferably containing at least 3 hydroxyl groups, in the presence of 50 to 300 :parts by weight of certain oils or fatty acids. Reaction temperatures vary between about '350 to 500 "F., especiallyabout 350 to 450 F., the maximum times required at "said temperatures being about 10 hours to as low as 0.5 hour, about 1-4 hours being normally adequate. "The oils which are preferably fatty oils advantageously comprise about 40 to 70 weight percent of the total composition whereas fatty acids generally comprise about to 60 weight percent thereof.

Starting with cyclopentadiene one obtains according to the process of this invention, alpha-dicyclopentadiene- 3,7-dica'rboxylic acid which was first prepared by Thiele: Berichte 34, "68 (1901) "by treating 'cyclopentadiene with metallicpotass'iumwith subsequent gassing of the potassium cyclopentadiene with carbon dioxide at atmospheric pressure. Decomposition of the (ii-potassium salt with acid yielded the "above dicyclopentadiene .dicarboxylic acid. As he stated in a footnote, 'Thieles attempts to cause 'cyclopentadiene to react with sodium were unsuccessful.

It has been found that dicyclopentadiene dicarboxylic acid and other dialkyl homologues of this acid may be readily prepared in high yields by reacting metallic sodium which has been dispersed to 'a'finely divided state, that is, to an average particle size of less than 50 microns in diameter, with monomeric cyclopentadiene or alkyl "ice -C0 preferably at superatmospheric ressures up to 1000 The sodium employed in this "reaction :isin'the form of a finely divided dispersion wherein the particles have an average size of less than 50 microns in diameter. Dispersion is obtained, for example, by mechanical means either Wlth'OI' without the aid of emulsifying'or dispersing agents. The alcohol activator is substantially anhyd'rous' alcohol, such as the low molecular Weight :aliphatic alcohols such as methanol, ethanol, :isop'ropa'nol, etc. Alcohols containing up to four carbon atoms per molecule are suitable but methanol, :ethanol or isopropanol are preferred. The alcohol is "employed :in relatively small amounts, that is, less than '1 mol equivalent based on the sodium and usually in amounts less than V mol equivalent. The alcohol serves to activate the sodium either by removing surface impurities contained thereon or by forming small quantities of alcoholate. Gassing with carbon dioxide is carried out at pressures above atmospheric, up to 1000 '-p.s.i.g'., for best yields. Good reaction is obtained at 5010 1 000 has. but since the tank pressure of CO as handled commercially is usually about 900 to 1000 p.s.-i:'g. this latter pressure is preferred.

While frequent reference is made in the literature to the use of metallic potassium for reacting with the methylene group of 'cyclopentadiene so as to form cyclopentadienyl potassium, no references have been found where the corresponding sodium salt was made by direct reaction of sodium with cyclopentadiene. If sodium is previously dispersed to a very finely divided state, preferably having a particle size of less than 50'micron-s in d-iameter,-e.g., by mixing With xylene, heating to above the melting point of the sodium and then passing "the mixture through "a high-speed colloid mill andcont'inuingthe operation until the temperature falls below the solidification point of the sodium, one obtains the sodium in a highly reactive state. With sodium in such a finely divided state some reaction may be obtained with cyclopentadiene, but the reaction tends to 'be relatively slow.- If to a tr-role of dispersed sodium there is added 1 to 2 grams cf anhydrous ethyl or isopropyl alcohol so as to activate the sodium either by removing, by means of solution, surface impurities or by forming small quantities of sodium alcoholate, immediate reaction may be -obtained when a mole of monomeric cyclopentadiene is added to the dispersed sodium. Under these conditions the 'cyclopentadienyl sodium is readily formed, and when this sodium salt is then transferred to a suitable pressure-resistant vessel and treated at super-atmospheric pressure with carbon dioxide one obtains almost exclusively the disodium salt of the dicyclopentadiene dicarboxylic acid having "a; :minimum of sodium carbonate orv bicarbonate present. In distinction to the use of carbon dioxide under pressure, if one gasses the mixture of the sodium or potassium cyclopentadiene with carbon dioxide at atmospheric pressure a large proportion of the mixture ends "up as sodium carbonate or bicarbonate, giving ultimately poor yields of the desired dicar'b'oxy'lic acid.

The dicyclopen'tadiene dicarboxylic acid has many use ful properties industrially, e.g., higher alcohol esters of 5 either the unsaturated acid or 'the:fully hydrogenated acid are useful as solvents and plasticizers for resins anaconing materials. It is also useful as amodifier for the production of alkyd resins when 'mixed with other suitphthalic anhydride and glycerol.

' 3 able ingredients and may serve as a basic material for the production of polyester types of lubricants, as an ingredient of specialty greases and as a source of other compounds.

The production of conventional alkyd resins generally involves the condensation of a tn'functional alcohol and adibasic acid. Such alkyd resins may be prepared from The basic resin may then be modified by incorporating therein certain saturated-and unsaturated fatty acids, non-drying oils, semidrying oils, drying oils, maleic anhydride-treated oils, styrenated oils, dihydric and polyhydric alcohols such as ethylene glycol, and pentaerythritol, as well as monoand di-glycerides. For a review of the development of alkyd-type resins reference may be made to Industrial and Engineering Chemistry, vol. 41, pages 716, 726

A major factor in the cost of production of all alkyd resins and especially alkyd resins derived from polyfunctional alcohols with dibasic acids such as phthalic anhydride is the relatively high temperatures and long times required in cooking varnishes made from said resins in order to obtain a commercially acceptable low acid number, viscosity, etc.

.It has now been discovered that, if dicyclopentadiene 'dicarboxylic acid and/or its above-mentioned alkyl or hydrogenated derivatives are substituted for phthalic anhydride in a typical alkyd resin formulation, the cooking time may be drastically reduced and lower temperatures may be employed and yet resins characterized by satisfactory acid numbers and viscosities may be obtained. Surface coatings derived from the aforesaid acids, according to the invention, of both the pigmented and unpig- -mented'type, exhibit superior drying rates, surface hardness, and gloss. The alkyd resins according to the present invention further have excellent resistance to water,.

tion may be made in which the dicyclopentadiene dicarboxylic acids replace phthalic anhydride in toto or in part or may comprise mixtures of dicyclopentadiene dicarboxylic acids with maleic acid, fumaric acid, and/or other acids reactive with polyfunctional and especially trifunctional alcohols. The alkyd resins of the present invention, made from aforesaid dicyclopentadiene dicarboxylic acids, may also be mixed with other surface coating compositions such as phenolic resins and/ or oleoresinous varnishes.

The following examples more fully explain the present invention but are not to be considered as limiting since they are given for the purposes of illustration only:

-EXAMPLE 1.CYCLOPENTADIENYL SODIUM Twenty-three grams of sodium are added to 500 ml. of xylene contained in a one-liter stainless steel beaker which is heated by means of a hot plate to a temperature of l20125 C. At this point a homogenizer-type of mixer, available commercially as a Homomixer," is immersed into the mixture of molten sodium in xylene and the mixer run for a period of approximately 15 seconds. At the completion of the run, the mixer is rinsed with approximately 100 ml. of xylene so as to wash off occluded sodium, and the entire mixture of dispersed sodium in xylene transferred to a one-liter flask fitted with (an eificient stirrer, thermometer, dropping funnel, and

reflux condenser.

To the well-stirred mixture is then added g. of freshly cracked and distilled monomeric eyclopentadiene boiling at 40-41 C., representing a 20% excess of the diolefin over the sodium. Just prior to addition of the diolefin there is added to the flask one or two ml. of anhydrous ethanol or isopropanol. With addition of the diolefin an immediate rise in temperature is noted, and the temperature of the flask contents is maintained within the limits of 30-35 C. by means of external cooling, using if necessary, a bath composed of solid carbon dioxide and alcohol. Addition time for the diolefin is usually in the neighborhood of one hour, and further stirring is continued for at least another hour at the same temperature in order to insure full reaction. The sodium changes from a dark gray powder to a voluminous precipitate having a white to a light gray appearance.

The cyclopentadienyl sodium may be reacted with alkyl halides, acid chlorides or esters of chloracetic acid to give respectively: dialkyl dicyclopentadiene, diketones of dicyclopentadiene, and his (carboxymethyl esters) of dicyclopentadiene.

EXAMPLE 2.-DISODIUM DICYCLOPENTADIENE DICARBOXYLIC ACID The flask contents from Example 1 are then charged to a bomb capable of withstanding pressure in excess of 1000 lbs. The bomb should be of a suitable resistant material such as stainless steel, nickel, Inconel, Monel or may be a silver-lined bomb. The bomb is fastened into a shaking machine and charged with full tank pressure of carbon dioxide which will normally be within the limits of 900-1000 lbs. per sq. in. gage. When charging with carbon dioxide an immediate rise in temperature is noted and afall in pressure in a closed system occurs indicating rapid reaction of the carbon dioxide. The system is repressured over a period of V1 hour to full tank pressure until no further pressure drop is noted. The mixture is then allowed to shake for a period of approximately 12 hours, during which time the initial rise in temperature to about 60 C. maybe increased by external heating to about C. Additional heating is not entirely necessary in order to obtain complete reaction but does hasten the reaction time so that with heating, as little as 2 hours is sufiicient. Shorter times may be employed if better mixing is available, such as propeller or turbo mixers. At the completion of the run the excess carbon dioxide is bled off, the bomb contents dumped into a Buchner funnel, and the salt washed with light naphtha or ethyl ether in order to remove excess solvent and small amounts of polymer. There is obtained a yield of from 128 to 134 g.of product varying in color from white to a light cream color.

The material has a low density and very fine particle size, exhibiting fluid flow characteristics in a dry state.

EXAMPLE 3.DICYCLOPENTADIENE DICARBOXYLIC ACID The sodium salt prepared in Example 2 is conveniently converted to the free acid by dissolving the salt in water, boiling for a few minutes and precipitating the acid by addition of dilute HCl and recovering the acid crystals by filtration. The crude product is recrystallized from approximately 50% aqueous methanol or approximately 70% aqueous acetic acid. A perfectly white crystalline acid is obtained having a melting point of 210 C. and a neutralization equivalent equal to 509 mgm. KOH/gm. It possesses a formula which may be illustrated by the following structure:

3 CH 4 HCCOOH 9/ \H/ C H CODE 0 CH Hi 1 lln 10\ /H 1 assesses.

The above reactions described in Examples 1, 2, and If are believed to be adequately described by the followmg series ofiequati'ons no COONa 4 21101 --p H 0 QB: 3O

.rro -coom n HC/ c--cn g HC-COOH I N n on 4' -'DISODIUM DIME'LHYIL: DICXFCLO- PENEIWD IENE DTCARBOXYLIQ ACID Seventy-five grams of methylcyclbpentadiene" (boiling point" 731 Ci) wasreacted at: a temperature off C. witli 23 grams of sodium dispersedih SOO'mI-I olf xylene. The" sodium salt was then transferred" to a silviir liiied vliomb' having; a capacity. of I18 mereand" charged with CO at a gage'pressur'e'of940#/si1. inchi. An immediate rise in temperature and" a; drop in: ressure occurred indicating, extensive reaction; The bomb? was represented and? allowed to shake for 3' hours without? additionafheat sb i ppliedv v r Deepening, the bomb, tilteringtlie solid andfwa'shi'ng' with'eeth'er a white solid saltwasf obtainedl'weigliingf 135.8 grams. Decomposition offthe salt; with aci'flfand recrys tallization'. from 70% acetic acid yielded a. whiteacid; melting at 2221-223 C; having" a neutralization equival'cntof 4'52. mgm'. KOIT/gm: Analysis by combustion gave; the following;

, i Round Them 014 1110] fieroent flarbon, Q. 6732 67:72 Baccarat-Hydrogen; 1 6:63? 6:50

v The following equations represent the chemical reactions involved? in this preparation;

CHrG 0*0-011.

, in; Ire- :5 1r

Niifb$=lb5itl0m er meenyr; radical; (en-9 shown in above 8%??1210118 is not knowmwithe cermmtmsndtisator'mnstration 0 a4 Althoughzthe above examples describe thep'repar'ation ofdicarbox'ylieacids fromrrelativel'y pure oyclopentadiene methyl; cyclopentadiene; good yields of High quality aoidsra're also obtained by reactingmixtures ofthese'tiwo components, for. example, suitable; mixtures may co'ntai'n 9401-10?" of cyclopentadiene and. -10% of'me'thyl cyclopentadie'ne. In addition, vapor phase steam -cracked hydrocarbons boiling; in the, range ofcyclopenta'diene and methyl cyclopentadi'ene containing; paraifiiis and atematics as diluents. may also be employed The products comprise a mixture of; the two: acids, namely, dicyclopentadiene dicarboxylic acid and" dime'thyldi'cyclbp'ehta diene dicarboxylic. acid.

Hydrogenated dicyalodin e carboxylic acids ine r alkyd. resins It. is know nthat" the dimethyl' ester"of dicyclopentadiene di'carbo'icyli'cv acid" can; depol'yme'rize to the" monomeric methyl ester of cyclopen'tfdiene carboiiyli'c acid when Heated: to crackingtemperatures ofabout'a'bove 200' It 'h'a's now beendiscovered,that-progressivehydrogeuation of the acid's of? the invention tothe dihydio and tetrahydro dicyelop'entadiene dicarboxylic acids 'and alkyl derivatives thereof? imp arts: improved stability to v the resulting acids and esters thereo'fand also'renders-said acids moresuita'ble for'u'se the production of? certain alkyd resins of the invention where the reactive compounds and resins are subjected to high temperatures;

A representative processof the present invention involves making a cyclodienyl sodium compound as abovedescribed, by reacting at pressures of about SO to 1000 p.s.i.g. monomeric cyclopentadienew with very finely divided metallic sodium at temperatures of about 10 to 40 C. in the presence of a" small amount of an anhydrous alcohol as an activator. The 'dienyl f sodium compound is then carboxylated with carbon dioxide) at temperatures between about 30 to 1.00" C. (e.q .l 60 6) to produce the corresponding sodium salt' of the acid. Finally the desired carboxylic acid can be obtained from the fglium salt by additiom of hydrochloric acid or the 1' The resulting dicyclopentadiene dicarboxylic acid, is usually a mixture of endo and exo isomers if the carboxylation temperature is in the range of about C. to 0 C. However, if the carboxylation is at about 50 to 100 C., the product is substantially all endo isomer. The above acid and its alkyl homologues have been found useful as a substitute for phthalic or maleic acids in a variety of reactions, as a starting material in the manufacture of polyester type lubricants and resins, and particularly in the manufacture of modified alkyd resins, as above described. However, in many of these uses the dicyclopentadiene dicarboxylic acid has various slight shortcomings. For instance, some of the previously known acids of this type have tended to undergo partial cracking as above mentioned, decarboxylation, as well as undesirable gelation when heated. As a result, some of the products prepared therefrom by means of high temperature reactions have "lacked uniformity or may have exhibited undesirably dark color. However, the great preponderance of the products formed have been satisfactory.

As above-mentioned, hydrogenation of the aforementioned dicyclopentadiene dicarboxylic acid or of its alkyl substituted homologues gives dicarboxylic acids which are more stable and in some respects superior to the original unhydrogenated acids. For instance, unlike the unhydrogenated acids, the corresponding dior tetra-hydro'genated compounds form perfectly stable diesters of alcohols of 1 to 13 carbon atoms, e.g. methyl, ethyl, isooctyl, tridecyl, etc., which may be distilled without cracking, decarboxylation or polymerization.

However, alkyd resins produced from unhydrogenated,

dicyclopentadiene dicarboxylic acids have special utility when used in conjunction with other reactive unsaturated materials since depolymerizationand co-reaction may take place with beneficial effects. For example, alkyd resins produced from the unsaturated acids according to the present invention, when compounded and cooked with oleoresinous varnishes, having highly unsaturated oils as a component, form eo-reactive products showing improved physical characteristics and performance. Also, it is obvious that it is less expensive to omit the hydrogenation step for those formulations where the improved thermal stability of the hydrogenated acids are not required.

The basic raw material from which essentially all of the compounds of this invention can be derived whether hydrogenated or unhydrogenated includes dicarboxylated dimers of cyclopentadiene, alkyl-substituted cyclopentadiene and mixtures thereof. Of foremost practical importance at present are dicyclopentadiene dicarboxylic acid, dimethyldicyclopentadiene dicarboxylic acid (which is a derivative of methylcyclopentadiene) andmethy'ldicyclopentadiene dicarboxylic acid, which is a derivative .of a mixture of cyclopentadiene and methylcyclopentadiene. Also, by hydrogenating the above dicyclodiene acids in such a manner that at least one, but preferably ,both of the double bonds originally present are saturated with hydrogen, .the dihydro and/or tetra-hydro di- ;cyclopentadiene dicarboxylic acids are formed as more fully described hereinafter. This hydrogenation can be illustrated by the following equations:

lowing the hydrogen pressure drop. prepare the dihydro acid, either the proper amount of one hydrofuran, etc.

mole of hydrogen per mole of acid can be charged to begin with, or an excess of hydrogen may be charged and the hydrogenation may be arrested as soon as a significantchange in the rate of hydrogenation is observed.

The reaction proceeds similarly when the corresponding derivatives of methylcyclopentadiene and related more highly alkylated cyclopentadienes are used.

The hydrogenation can be carried out at hydrogen pressures of about atmospheric to 2000 p.s.i.g., preferably at 15 to 150 p.s.i.g., and with the aid of various catalysts such as Adams platinum oxide (PtO Raney nickel, etc. Also, since the dicyclodiene dicarboxylic acids are relatively high melting solids, it is advantageous to add a suitable solvent to the reaction mixture in a .quantity suflicient to dissolve the original dicarboxylic acid. Suitable solvents include alcohols such as methanol, ethanol, and isopropanol as well as other inert oxygenated solvents such as acetic acid, dioxane, ether, tetra- The amount of solvent added may equal about 5 to 50 times the weight of the dicarboxylic acid. The hydrogenation is carried out at temperatures between about 20 to 100 0., preferably 30 to C.

The actual working and nature of the invention is particularly illustrated by the following preparation of tetrahydrodicyclopentadiene dicarboxylic acid. In the following example, as throughout this entire specification, it will be understood that all amounts, proportions and perasamaa 9 centages of materials are expressed? era a weight Basis unless indicated. otherwise.

- Methyl esters of: the unsaturated: and faith acids: were prepared hy: refluxing; the: respective acids: ion six hours with arr excess of methanol containing a. smallam-ount' oft sulfuric( acid, removing; the: alcohol: and? in:

Twenty-two grams BT01?) ofidibyclbpentadiene 5 organic: acid and crystallizing; tram petroleum, ether; carboxylic acid was dissolved in 315 grams 400 Distillation:- oh the. two esters: showed no? decomposition P anhydrous ethanolill P S b fl g P for the hydrogenated material. whereas. the unhyrlzo. ltY-Of 13001111. and CQIl'llfiCfGdWO a hydro'gen storage-tank genated ester;cracked sevepelyp having R p y Of 810 ml- The tree space in the A. series of alkyd resins. were; prepared. firomr various; System was 7625 Tlle' f y acid used was 1 dicyclopenta'dienedicarboxylici acids. Exhrriplsrtd-B, a White Crystalline Solid having? ti P P 2 inclusive show resins; which were? prepared: from C. an'd a neutralization equivalent 015 509 mgnr. KOH/gm. dro'genatei acids, Examples 9: and 10: how? pesin3 13 1,7311- 0 of Adams R 2 C y W added the pared from di-hydro dicyclopentadiene. dicarboieylio. acid alcoholic: solution of the acid; the air exhausted from (Example 9) d fr tetrwhydm dicyclopentadiene the bottle and the system wasbtlien' filledwith' hydrogen 15 carboxylic acid (Example 10a. to a pressure of 41 p.s'.i.g. tr shaking; there was an p immediate absorption of hydrogen until the pressure EXAMPLES dropped to 3115 p.s.i.g;, representing- 012 mol of hydro- A fatty oil modified alkyd resin was prepared: by gen ahs'orh'e'd in a perio'dofabout" 30*minut'es; The hycooking: the following recipe: droge'n passage was observed tohdropat mto're rapid Recipe: rate in t e st part, correspon ing? to e ormat-i'on v of. the dihydroacid, than in thelatterparti At the end 5.33,; I I Ban! of the. reaction the reaction mixture wasfil'tere'd to sepa- 95%glyceml I v y n rate the catalyst from the alcoholic solution and' the Di CFacidsd """i" ff f f' 2- 1, alcohol was evaporated from the' solution" on a steam Leadpbxide (P130) p bath under an atmosphereof nitrogen. The'solidresidue I i if??? was dissolved in 100 ml; of 50% ethanol and-recrystal- 1'Dlcyelopenthdlene?dlcnblxylwacids lized. In: each example, an oil' and glycerol were mixed and The resulting tetrahydrodicyclopentadiene dicarboxylic heated under an inert atmosphere tifca'rbomdioxide; the acid. product was recovered irr an essentially quantitative lead oxide being' added when the temperature reached yieldin the form. of snow white crystals; having a mel't- 3001 F. Heating was continued until a test sam'ple was ing point" of 193-194" C. on a copper bar; Titration soluble in ten" parts" of methanol at which point? the" diof a sample weighing 03143 gramrequire'd- 2711 5 ml. of cyclopentadiene dicarhoxylic acidswere; added over a 0.1034 N alkali. This corresponds an. equivalent period of about one-half: hour; The? tempcrank-e weight of. 112.0 as against a theoreticalweight of 112.1. raised" to. either a temperature level ch31? F. 011425 A test'foriunsaturation by reaction with bromine-indicated F., as indicated in the examples; and held 'at said level that the product was completely saturatedl These until bodying was complete for the required" times in.- analytical results are indicative of. the high purity of dicated hereinafter. the hydrogenated acid ohtained. Reduction of dimethyl I In Examples 6-8, the fatty oilemodified alkyd resins dicyclopentadiene dicarboxylic acid in the: same manner 40 were Produced from dicyclbpefltadiem i y l?" acid as above,. yields the tetra-hydro acid. and cooked with soya oil, dehydrated castor oil", linseed The dihydrodicyclopentadiene' dicarhoxylicj acid was Oil, and Y? respectively- I I prepared in the same manner as just described, except In Examples 9 and. I0,.soya oil-modified alkyd. resins that hydrogen was charged inLan. amount equal* to only were p li by cooking the recipe hel'el'jllfiefore-dsig' one mol per mole of dicyclopentadiene dicarboxylic acid. nated as: Recipe A except that an equivalent amount The separated product was recovered in the form of'white of the dihydroand tetrahydro dicyclopentadiene dicarcrystals upon recrystallization. from al'coholi When hoxylic acids were substituted for. the, unhydro'gena'ted tested with bromine, it showed an unsaturation corredicyclopentadiene dicarboxylic. acids given in. Examples sponding to. one double bond per mole of'the' dicarboxylic 6m 8. v acidl product. The dihyd'roacid remained stable when For the purpose of comparing.the alkydresins.of. the heated" under a blanket of'nitrog'en" at a temperature of present invention with. a conventional. alkyd. resin,v a. con. 250 C. for periods of 30 minutes and more, whereas trol-was-likewise made up:of.the.above.' Recipe A?"e'xcept the original unhydroge'nated dicyclopentadiene dicarthatphthalic-anhydride was used instead. of. the'.-dicycloboxylic acid, tends to decarboxylateanddepolyn'ieriie at pentadiene dicarboxylicacids.v The allcydlresins referred temperatures as low as' 200C. Thi ncre'ased stability is of greatimportance when the acid is to be used in various high temperature reactions such as the preparation of polyesters, etc.

to above, were then reduced to. a: specified NA'LM. (non-volatile material content). by. the additionofimincral spirits. thereto, the. inspections being. shown in. the following-table.

mnnn-.-onaaxornmsrros OF ALKYD nnsms Example No; Control 6 7 8 v 9. 10,.

Acidic-Material Used; Phthalic' Iln- D101: Acid L. =D1CpAcidL--- ,DLCp Acidl-.- DihydmIDiGp Tetrahydi-o l hydride. 1 AcidJ Di'Op A-oid m1 Snv a .Soya. Dehydrated Linseed Soyat- Soya.

Castor Oil. I, Time to reach max. Temp. (1m) 3:0; 2.8. 2.8 2.8. 3:0. 20'. Max. Temp. of cook required, F p ,425 37 v37 37 425? 425'. Required'limeat max. Temp. (Hrs); 1*.2. 2 2.5. '4 5 2.. Wt. percent 011 in N.V M 50;" 50 50 50; Wt. percent Ester in N .V.M- p 50 50 l 50 1 50;; Wt. percent/N.V.M'. in Min. Sp. 80111.3". m 50 50 50 50,. Viscosity: Gardner- X-Y Z U 'Y 'W ii Color: Gardner-1933 Std. 10.5 11.5.- 11 Acid Number (on N.V.M.). I 1 I 13.... 4 10 6.7

1 D1 Cp=d1cyclopentadiene dlcsrboxyllc:

= May be varied betweenahout 20r-70Wt.percenaN.V.M..to form a varnish the resin prererablyoantalningmaior proportionality weight oi the resin solvent.

alkali resistance and grease resistance.

'In' the sboveExamples 6-10, compared to the control, it is shown that all alkyd resins of the present invention required drastically less time for cooking at the maximum temperatures (i.e. 1.2 to 3.5 hours) whereas the phthalic anhydride-type resin control required 16 hours. The resins of the present invention derived from hydrogenated dicyclopentadiene dicarboxylic acids required slightly higher cooking temperatures and a slightly longer cooking time than did the resins of the invention derived from unhydrogenated dicarboxylic acids. However, the resins derived from hydrogenated acids according to the invention, as pointed out before, are more stable upon exposure: to heat.

EXAMPLE 11 Air dried films were drawn on mild steel panels from all resin solutions (i.e. varnishes containing 50% N.V.M.) of Exmaplcs 6-10 and also the control after incorporating therein 0.25 wt. percent of a commercial antiskinning agent (National Aniline Companys Antiskinning Agent ALS.'A.), lead naphthenate, and cobalt naphthenate (0.5 wt. percent lead and 0.05 wt. percent cobalt, percentages based on vehicle solids). The thicknesses of the dried films were uniformly 1.15:0.15 mil. The properties of the air dried films containing the alkyd resins prepared as in Examples 6-10 were compared to air dried films prepared from the conventional phthalic anhydride alkydrecin control, during drying for drying characteristics,

and after drying for hardness, flexibility, water resistance, In each instance the surface coatings made from the alkyd resins of the present invention derived from dicyclopentadiene dicarboxylic acid compounds were equal or superior to the above surface coating prepared from the conventional phthalic anhydride alkyd resin control; otherwise of the ,same formulation.

EXAMPLE 12 Similarly, films of all resins (50% N.V.M.) were drawn on the same steel and baked for 30 minutes at 300 F. in a forced air circulation oven. The films contained 0.25% of the commercial antiskinning agent of Example 11, and 0.02% cobalt as the naphthenate (based filrns'prepared from varnishes containing the conventional phthalic anhydride resin control during baking for drying characteristics, and after baking for hardness, flexibility, water resistance, alkali resistance and grease resistance. In each instance the surface coatings made from the alkyd resins of the present invention derived from dicyclopentadiene dicarboxylic acid, dihydro dicyclopentadiene dicarboxylic acid and tetrahydro dicyclopentadiene dicarboxylic acid were equal or superior to the above surface coating prepared from the conventional phthalic anhydride alkyd resin control; otherwise of the same formulation.

EXAMPLE 13 In a similar manner, black and white enamels were made from the 50% resin solutions of Examples 6 to aswell as the control. Enamels prepared from the resins of the-present invention may contain about 1-50 wt.

percent (preferably 2-32 wt. percent) of a pigment, the amount depending upon the nature of a specific pigment. employed. Obviously common enamel pigments other than black or white pigments may be employed. The compositions of the white enamels of the present example were as follows:

31.9 wt. percent TiO, (Ti pure R-610) I 31.9 wt. percent resin solids 36.2 wt. percent mineral spirits The compositions of the black enamels were:

2.09 wt. percent super spectra carbon black 38.79 wt. percent resin solids 59.12 wt. percent mineral spirits Panels were made from all resins on the same steel as above in Examples 11 and 12. In one series of tests the panels were coated with the enamel and air dried according to the general procedure of Example 11, whereas in another series of tests the panels were coated and baked according to the general procedure of Example 12. In each series of tests, the resulting enamel films produced according to the present invention were compared to films of enamels containing the conventional phthalic anhydride resin controls otherwise of the identical composition and under the identical conditions of drying or baking. All panels formed were then exposed to outdoor weathering tests. The enamelled panels prepared according to the present invention compared favorably with the control panels made from the phthalic anhydride alkyd resin control.

While there are above described a number of specific embodiments of the present invention, it is obviously possible to produce other embodiments and various equivalent modifications and variations thereof without departing from the spirit of the invention or the scope of the appended claims.

What is claimed is:

1. A process for preparing improved alkyd resins which comprises reacting to parts by weight of dicyclopentadiene dicarboxylic acid with 20 to 60 parts by weight of glycerol in the presence of 50 to 300 parts by weight of soya oil at a temperature between about 350 and 450' F. for about 1 to 4 hours.

2. A modified alkyd resin composition which comprises the product of the reaction of 20 to 60 parts by weight of glycerol, 100 to 150 parts by weight of tetrahydrogenated dicyclopentadiene dicarboxylic acid, and 50 to 300 parts of soya oil at a temperature between about 350 and 500 F.

3. A varnish which comprises the modified alkyd resin composition of claim 2 diluted with sufficient amounts of resin solvent to reduce the non-volatile material content to between about 20 and 70 weight percent based on said resin.

4. An enamel which comprises the modified alkyd resin of claim 2 diluted with sufficient amounts of resin solvent to reduce the non-volatile material content to between about 20 and 70 weight percent based on said resin, and containing between about 1 and 50 weight percent based on said enamel of a pigment.

5. A process for preparing improved alkyd resins which comprises reacting about 100 to 150 parts by weight of a dicyclopentadiene dicarboxylic acid selected from the group consisting of dicyclopentadiene dicarboxylic acid, methyl dicyclopentadiene dicarboxylic acid, dimethyl dicyclopentadiene dicarboxylic acid, the diand tetrahydrogenated products of the first three members of this group, and mixtures thereof, with about 20 to 60 parts ,by weight of a trihydric alcohol in the presence 2 of a coreactant selected from the group consisting of 40 to 70 weight percent of fatty oils based on the product alkyd resin and 30 to 60 weight percent of fatty acids based on said resin, at temperatures between about 350' and 500 F. until a substantial conversion of the reactants to an alkyd resin is obtained.

6. A process according to claim 5 wherein the coreactant is soya oil.

7. A process according to claim 5 wherein the coreactant is castor oil.

8. A process according to claim 5 wherein the acid is dihydrodicyclopentadiene dicarboxylic acid.

9. A process according to claim 5 wherein the acid is tetrahydrodicyclopentadiene dicarboxylic acid.

10. A process according to claim wherein the acid is dimethyl dicyclopentadiene dicarboxylic acid.

11. A process according to claim 5 wherein the acid is dicyclopentadiene dicarboxylic acid.

12. A modified alkyd resin composition which comprises the product of the reaction at a temperature be tween about 350 and 500 F. of to parts by weight of a trihydric alcohol; to parts by weight of a dicyclopentadiene dicarboxylic acid selected from the group consisting of dicyclopentadiene dicarboxylic acid, methyl dicyclopentadiene dicarboxylic acid, dimethyl dicyclopentadiene dicarboxylic acid, the diand tetrahydrogenated products of the first three members of this group and mixtures thereof, and a coreactant selected 14 1 from the group consisting of 40, to 70 weight percent of fatty oils based on said resin composition and 30 to 60 weight percent of fatty acids based on said resin composition.

References Cited in the tile of this patent UNITED STATES PATENTS 1,983,460. Hopkins et al. Dec. 4, 1934 10 2,397,240 Butler Mar. 26, 1946 OTHER REFERENCES Thiele: Berichte, Deut. Chem., vol. 34, pages 68-70 (1901) (copy in Scientific Library). 

12. A MODIFIED ALKYD RESIN COMPOSITION WHICH COMPRISES THE PRODUCT OF THE REACTION AT A TEMPERATURE BETWEEN ABOUT 350* AND 500*F. OF 20 TO 60 PARTS BY WEIGHT OF A TRIHYDRIC ALCOHOL:100 TO 150 PARTS BY WEIGHT OF A DICYCLOPENTADIENE DICARBOXYLIC ACID SELECTED FROM THE GROUP CONSISTING OF DICYCLOPENTADIENE DICARBOXYLIC ACID METHYL DICYCLOPENTADIENE DICARBOXYLIC ACID, DIMETHYL DICYCLOPENTADIENE DICARBOXYLIC ACID, THE DI AND TETRAHYDROGENATED PRODUCTS OF THE FIRST THREE MEMBERS OF THIS GROUP AND MIXTURES THEREOF AND A COREACTANT SELECTED FROM THE GROUP CONSISTING OF 40 TO 70 WEIGHT PERCENT OF FATTY OILS BASED ON SAID RESIN COMPOSITION AND 30 TO 60 WEIGHT PERCENT OF FATTY ACIDS BASED ON SAID RESIN COMPOSITION. 